This invention relates to a microwave device, and more specifically to a microwave device with fine particles arranged in a regular pattern on a substrate.
As devices employed for a wavelength range of from microwaves to millimeter waves, those making use of semiconductor devices have been used primarily to date. However, their time constants are increased to hardly ignorable large levels due to an increase in their junction capacitances and series resistances when they are used at higher frequencies. Research has been underway from the viewpoint of minimizing junction areas as much as possible or developing devices which make use of point-to-point contact between metals. As one exemplarly outcome of such research, a deposition film with an island structure has been prepared under suitable conditions so that a number of MIM diodes have been brought into a mutually-connected state. Using such deposition films with the island structure, there are fabricated high-speed detectors and frequency mixers both of which can successfully respond to a wavelength range of from microwves to the infrared range.
Furthermore, a thin film which is formed by vacuum-depositing on a substrate a superconducting metal in the form of particles can be also used as detectors and mixers which exhibit high sensitivities to a wavelength range of from microwaves to the far infrared range, because a number of Josephson junctions formed between adjacent particles are connected together in a random pattern.
In devices making use of vacuum-deposited particles, currents tend to flow along certain specific branched paths and coherent modes can hardly be established throughout their respective systems since their structures are not uniform. As a result, their detection or oscillation characteristics are not sufficient.